Methods and devices for testing a device under test using a synchronization signal

ABSTRACT

Embodiments of the present invention provide an automated test equipment (a “tester”) for testing a device under test, including a bidirectional dedicated real-time handler interface. Some embodiments use the bidirectional dedicated real-time handler interface to transmit a synchronization signal between the handler and the automated test equipment to synchronize a function of the handler in real-time, which advantageously improves testing efficiency and accuracy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims priority to and is a continuation ofInternational Application No. PCT/EP2021/071817 filed Aug. 4, 2021,which is incorporated herein by reference in its entirety as if it wereput forth in full below. This Application is related to and incorporatesby reference the following co-pending U.S. Pat. Applications: U.S. Pat.Application Serial No. ____, filed Jan. 31, 2023, Attorney Docket No.ATSY-0099-02N01US; U.S. Pat. Application Serial No. ____, filed Jan. 31,2023, Attorney Docket No. ATSY-0099-04N01US; U.S. Pat. ApplicationSerial No. ____, filed Jan. 31, 2023, Attorney Docket No.ATSY-0099-05N01US; and U.S. Pat. Application Serial No. ____, filed Jan.31, 2023, Attorney Docket No. ATSY-0099-06N01US.

FIELD

Embodiments of the present invention generally relate to the field ofdevice testing. More specifically, embodiments of the present inventionrelate to methods and systems for device testing using real-timeinterfaces.

BACKGROUND

A device or equipment under test (e.g., a DUT) is typically tested todetermine the performance and consistency of the device before thedevice is sold. The device can be tested using a large variety of testcases, and the result of the test cases is compared to an expectedoutput result. When the result of a test case does not match theexpected output value, the device can be considered a failed device oroutlier, and the device can be binned based on performance, etc.

A DUT is usually tested by automatic or automated test equipment (ATE),which may be used to conduct complex testing using software andautomation to improve the efficiency of testing according to a testprogram, for example. The DUT may be any type of electronic deviceincluding a semiconductor device, wafer, or component that is intendedto be integrated into a final product, such as a computer or otherelectronic device. By removing defective or unsatisfactory chips atmanufacture using ATE, the quality of the yield can be significantlyimproved.

Complex digital devices such as, microprocessors, graphics processingunits, and microcontrollers may consume a relatively large amount power.Power consumption and device temperature profile may vary throughouttesting and may be test site dependent. Precise temperature control maybe important or even essential to test these devices in some cases wherea “flat” and/or predictable temperature profile is desired.

In addition, it is often important to provide testing equipment that iscapable of performing tests with a high degree of precision withoutadding a great degree of effort or complexity to the testing process.

SUMMARY

What is needed is an approach to DUT testing that achieves a compromisebetween temperature control efficiency, testing precision and complexityof the testing equipment. Accordingly, embodiments of the presentinvention provide an automated test equipment (a “tester”) for testing adevice under test, including a bidirectional dedicated real-time handlerinterface. Some embodiments include an interface having a triggerfunction, a fixed endpoint interface, an interface arranged on a testhead, or a number of lines/communication channels adapted to a specificcommunication task, without separate signal lines, for example. Thebidirectional dedicated real-time handler interface can be used totransmit a synchronization signal or other information to the handler inreal-time, and the transmitted signal can be test site specific. Thereal-time signaling advantageously improves testing accuracy andefficiency.

According to one embodiment, automated test equipment for testing adevice under test (DUT) is disclosed. The automated test equipmentincludes a test computer and a real-time handler interface coupled to ahandler. The real-time handler interface is operable to transmit atrigger signal from the test computer to the handler to trigger atemperature control function of the handler, and transmit asynchronization signal from the test computer to the handler tosynchronize another function of the handler, other than the temperaturecontrol function, in real-time.

According to some embodiments, the real-time handler interface isfurther operable to perform an active synchronization with the handlerbased on the synchronization signal, and the active synchronization isfree of any wait insertions.

According to some embodiments, the real-time handler interface isoperable to transmit calibration timing information to the handler, andwherein the handler is operable to perform calibration of the handlerbased on the calibration timing information.

According to some embodiments, wherein the real-time handler interfaceis further operable to transmit another signal indicating that the DUTis powered or biased in a predetermined manner.

According to some embodiments, the real-time handler interface isfurther operable to transmit another signal when a predetermined testcondition is satisfied.

According to some embodiments, the real-time handler interface isfurther operable to provide the synchronization signal to the handler totrigger a temperature measurement by the handler.

According to some embodiments, the handler is operable to perform athermal diode calibration according to the synchronization signal, andwherein the thermal diode calibration comprises a delta temperaturemeasurement, and wherein further the real-time handler interface isfurther operable to transmit real-time measurement timing information tothe handler for performing the thermal diode calibration.

According to some embodiments, the synchronization signal comprises timeinformation for performing a measurement by the handler.

According to some embodiments, the synchronization signal comprises atleast one of: test state information; and device state information.

According to a different embodiment, a handler for testing a deviceunder test (DUT) using automated test equipment is disclosed. Thehandler includes a circuit and a real-time tester interface coupled tothe DUT. The circuit is operable to receive a trigger signal from theautomated test equipment, trigger a temperature control function inresponse to the received trigger signal, receive a synchronizationsignal from the automated test equipment, and synchronize anotherfunction with the automated test equipment, other than the temperaturecontrol function, in response to the received synchronization signal.

According to some embodiments, the circuit is further operable toreceive a signal for performing an active synchronization with theautomated test equipment, and perform active synchronization with theautomated test equipment based on the synchronization signal, where theactive synchronization is free of any wait insertions.

According to some embodiments, the circuit is further operable toreceive calibration timing information from the automated test equipmentto determine calibration timing and perform calibration to test the DUTbased on the calibration timing information.

According to some embodiments, the circuit is further operable toreceive another signal from the automated test equipment, and othersignal indicates that the DUT is powered or biased in a predeterminedmanner.

According to some embodiments, the circuit is further operable toreceive a signal from the automated test equipment when a predeterminedtest condition is satisfied.

According to some embodiments, the circuit is further operable toreceive another signal from the automated test equipment that triggers atemperature reading and perform the temperature measurement based on thesynchronization signal.

According to some embodiments, the circuit is further operable toperform a thermal diode calibration based on the synchronization signalreceived from the automated test equipment, where the thermal diodecalibration comprises a delta temperature measurement, perform the deltatemperature measurement, and receive real-time measurement timinginformation from the automated test equipment for performing the thermaldiode calibration.

According to some embodiments, the synchronization signal comprises timeinformation, and wherein the real-time tester interface is furtheroperable to cause the circuit to perform a measurement based on the timeinformation.

According to some embodiments, the synchronization signal comprises atleast one of: test state information; and device state information.

According to another embodiments, a method includes transmitting atrigger signal to a handler via a real-time handler interface to triggera temperature control function of the handler, transmitting asynchronization signal to the handler via the real-time handlerinterface, and synchronizing another function of the handler accordingto the synchronization signal, other than the temperature controlfunction.

According to yet another embodiment, a method of testing a device undertest is disclosed. The method includes receiving a trigger signal froman automated test equipment via a real-time tester interface, triggeringa temperature control function in response to the received triggersignal, receiving a synchronization signal from the automated testequipment via the real-time tester interface, and synchronizing anotherfunction with the automated test equipment, other than the temperaturecontrol function, in response to the received synchronization signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthis specification, illustrate embodiments of the invention and,together with the description, serve to explain the principles of theinvention:

FIG. 1 depicts a top view of exemplary automated test equipment and anexemplary handler according to embodiments of the present invention.

FIG. 2 depicts a top view of exemplary automated test equipment and anexemplary handler using real-time interfaces according to embodiments ofthe present invention.

FIG. 3 depicts a top view of exemplary automated test equipment andexemplary handler using a test site specific signal according toembodiments of the present invention.

FIG. 4 depicts a top view of exemplary automated test equipment and anexemplary handler using real-time interfaces and a test site specificsignal according to embodiments of the present invention.

FIG. 5 depicts automated test equipment including a real-time handlerinterface and a handler including a real-time tester interface accordingto embodiments of the present invention.

FIG. 6 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process for providing atrigger signal to a bidirectional dedicated real-time handler interfaceaccording to embodiments of the present invention.

FIG. 7 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process for receiving atrigger signal from an automated test equipment via a bidirectionaldedicated real-time tester interface according to embodiments of thepresent invention.

FIG. 8 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process for receiving atrigger signal from an automated test equipment via a bidirectionaldedicated real-time tester interface according to embodiments of thepresent invention.

FIG. 9 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process for receiving atrigger signal from an automated test equipment via a real-time testerinterface to trigger a temperature control function according toembodiments of the present invention.

FIG. 10 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process for providing a testsite specific signal to a handler via a real-time handler interfaceaccording to embodiments of the present invention.

FIG. 11 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process for receiving a testsite specific signal from an automated test equipment to control atemperature control function according to embodiments of the presentinvention.

FIG. 12 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process for providing a testsite specific signal to an automated test equipment according toembodiments of the present invention.

FIG. 13 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process for receiving a testsite specific signal from a handler via a real-time handler interfaceaccording to embodiments of the present invention.

FIG. 14 is a flow chart depicting an exemplary sequence of computerimplemented steps of a process for providing a trigger signal via areal-time handler interface to a handler to trigger a temperaturecontrol function according to embodiments of the present invention.

FIG. 15 is a flow chart depicting an exemplary sequence of computerimplemented steps that perform a process receiving a trigger signal andan additional signal via a real-time tester interface according toembodiments of the present invention.

FIG. 16 is a block diagram depicting an exemplary automated testequipment and a handler with a test head according to embodiments of theinvention.

FIG. 17 is a diagram depicting an exemplary temperature controlfunction, e.g. a device temperature control function, according toembodiments of the invention.

FIG. 18 depicts two exemplary test sites, a first test site (Site 1) anda second test site (Site N) according to embodiments of the presentinvention.

FIG. 19 depicts an exemplary test flow that can use test suitesaccording to embodiments of the present invention.

FIG. 20 depicts an exemplary alarm handling process according toembodiments of the present invention.

FIG. 21 depicts an exemplary calibration function according toembodiments of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to several embodiments. While thesubject matter will be described in conjunction with the alternativeembodiments, it will be understood that they are not intended to limitthe claimed subject matter to these embodiments. On the contrary, theclaimed subject matter is intended to cover alternative, modifications,and equivalents, which may be included within the spirit and scope ofthe claimed subject matter as defined by the appended claims.

Furthermore, in the following detailed description, numerous specificdetails are set forth to provide a thorough understanding of the claimedsubject matter. However, it will be recognized by one skilled in the artthat embodiments may be practiced without these specific details or withequivalents thereof. In other instances, well-known methods, procedures,components, and circuits have not been described in detail as not tounnecessarily obscure aspects and features of the subject matter.

Portions of the detailed description that follows are presented anddiscussed in terms of a method. Although steps and sequencing thereofare disclosed in a figure herein (e.g., FIGS. 6-15 , for instance)describing the operations of this method, such steps and sequencing areexemplary. Embodiments are well suited to performing various other stepsor variations of the steps recited in the flowchart of the figureherein, and in a sequence other than that depicted and described herein.

Some portions of the detailed description are presented in terms ofprocedures, steps, logic blocks, processing, and other symbolicrepresentations of operations on data bits that can be performed oncomputer memory. These descriptions and representations are the meansused by those skilled in the data processing arts to most effectivelyconvey the substance of their work to others skilled in the art. Aprocedure, computer-executed step, logic block, process, etc., is here,and generally, conceived to be a self-consistent sequence of steps orinstructions leading to a desired result. The steps are those requiringphysical manipulations of physical quantities. Usually, though notnecessarily, these quantities take the form of electrical or magneticsignals capable of being stored, transferred, combined, compared, andotherwise manipulated in a computer system. It has proven convenient attimes, principally for reasons of common usage, to refer to thesesignals as bits, values, elements, symbols, characters, terms, numbers,parameters, or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the followingdiscussions, it is appreciated that throughout, discussions utilizingterms such as “accessing,” “writing,” “including,” “storing,”“transmitting,” “associating,” “identifying,” “encoding,” “labeling,” orthe like, refer to the action and processes of a computer system, orsimilar electronic computing device, that manipulates and transformsdata represented as physical (electronic) quantities within the computersystem’s registers and memories into other data similarly represented asphysical quantities within the computer system memories or registers orother such information storage, transmission or display devices.

Some embodiments may be described in the general context ofcomputer-executable instructions, such as program modules, executed byone or more computers or other devices. Generally, program modulesinclude routines, algorithms, programs, objects, components, datastructures, etc. that perform particular tasks or implement particularabstract data types. Typically the functionality of the program modulesmay be combined or distributed as desired in various embodiments.

Bidirectional Dedicated Interfaces for Dut Testing

Embodiments of the present invention provide systems and methods fortesting a device under test using a bidirectional dedicated real-timehandler interface. The real-time handler interface is configured toprovide a trigger signal to a handler, for example, to trigger atemperature control function. The real-time handler interface isconfigured to receive the signal from the handler, and the automatedtest equipment is configured to access, read, process, or analyze thesignal received from the handler.

FIG. 1 depicts a top view of exemplary automated test equipment 110 andan exemplary handler 130 according to embodiments of the presentinvention. FIG. 1 depicts an automated test equipment 110 including abidirectional dedicated real-time handler interface 120 and a handler130 including a bidirectional dedicated real-time tester interface 140.Furthermore, FIG. 1 depicts devices under test 152, 154, 156, 158, as anexample, arranged on the handler 130. Automated test equipment includesCPU 162 for executing instructions, such as instructions of a testprogram or test flow, and the CPU an access signals received over thebidirectional dedicated real-time handler interface 120. Automated testequipment 110 can be a test computer system, or a component of a testcomputer system, for example.

The interfaces 120, 140 are dedicated interfaces such that the handlerinterface 120 is configured to communicate with the tester interface 140and vice versa, as the interfaces are bidirectional. In addition, theinterfaces 120, 140 are real-time interfaces. Therefore, datatransmission times between the interfaces, e.g. a time between thebeginning of a sending process of a message at one interface and the endof the arrival of the message at the other interface, may be tailored(e.g., reduced) to increase temperature control timing of a device undertest 152, 154, 156, 158. Therefore, information exchanged betweenautomated test equipment 110 and handler 130 may be used for temperaturecontrol in real-time, or for other purposes, such as testing adaptationor testing evaluation.

The real-time handler interface 120 is configured to provide a triggersignal 122 to the handler 130 that triggers a temperature controlfunction. The handler 130 can be configured to receive the triggersignal 122 from the automated test equipment 110 via the testerinterface 140, and the handler 130 can be configured to trigger thetemperature control function in response to the received signal 122.

The handler 130 may be configured to cool and/or heat a device undertest 152, 154, 156, 158 to prevent overheating or reach a desiredtemperature. Trigger signal 122 may include information regarding anupcoming temperature peak of a device under test, and the handler cancounteract a thermal hotspot (or even a thermal runaway) of a deviceunder test 152, 154, 156, 158. The handler 130 includes a circuit 160that can access signals received from the real-time tester interface 140and can cause the handler 130 to perform tasks according to the signals,such as thermal management tasks, synchronization, etc.

Furthermore, the handler 130 can be configured to provide a signal 142to the automated test equipment 110 via the tester interface 140, andthe real-time handler interface 120 can receive the signal 142 from thehandler 130. The automated test equipment 110 accesses and evaluates thesignal 142 received from the handler.

The handler may transmit temperature information of a device under test152, 154, 156, 158 in real-time to the automated test equipment 110. Theautomated test equipment 110 may access and evaluate this informationand adapt a testing process thereto to prevent overheating of a deviceunder test. A test flow may be adapted or modified so that a coolingtime for a device under test 152, 154, 156, 158 between two sub tests isincreased. In addition, the trigger signal 122 may be adapted based onthe signal 142 received to instruct the handler 130 to adapt atemperature management strategy.

According to some embodiments, the bidirectional dedicated real-timehandler interface 120 may be configured to provide a synchronizationsignal to the handler 130. The handler 130 may be configured to receivethe synchronization signal via the bidirectional dedicated real-timetester interface 140. Based on the synchronization signal, the handler130 may perform other functions in synchronization with the automatedtest equipment 110 beyond triggering of the temperature controlfunction. For example, synchronization may be performed by the automatedtest equipment 110 to perform measurements, e.g., temperaturemeasurements of devices under test 152, 154, 156, 158, by the handler130 at a specific time. The measurements may occur with a certain timeresponsive to a stimulus of a device under test 152, 154, 156, 158.Signal 122 may include the synchronization signal, or thesynchronization signal may be transmitted as a separate signal.

According to some embodiments, the bidirectional dedicated real-timehandler interface 120 may be configured to provide a test site specificsignal to the handler 130. The handler may be configured to receive thetest site specific signal from the automated test equipment 110 via thebidirectional dedicated real-time tester interface 140. The handler maycontrol a temperature control function based on or in response to thetest site specific signal, such as cooling a specific device under test152. The signal 142 sent from the handler 130 to the automated testequipment 110 may also be a test site specific signal, such astemperature measurements of a specific test site or device under test152.

The bidirectional dedicated real-time handler interface 120 may beconfigured to provide another signal in addition to the trigger signal122. For example, the handler 130 may be configured to receive anadditional signal via the real-time tester interface 140, in addition tothe trigger signal 122. The additional signal may include controlinformation may be used for determining or modifying a temperaturecontrol profile or temperature regulation by the handler 130, and mayinclude information about one or more measured values determined by theautomated test equipment 110, one or more test state parameters, and/oralarm information. The handler 130 may be configured to use theadditional signal to control the temperature of one or more device undertest sites or devices under test 152, 154, 156, 158. The additionalsignal may include any information that can be used to improve thetesting of the devices under test.

The test state parameters may include timing information of upcomingpower supply changes for the devices under test 152, 154, 156, 158, andthe handler 130 may adapt its cooling strategy for the devices based onthe timing information. Furthermore, the handler may be configured toevaluate such information to decide how to adapt the temperaturemanagement. The additional signal may be a direct temperature managementstrategy informing the handler when and where to cool based on thetiming information, for example. When a device under test malfunctions,the handler 130 may immediately cool a device under test to preventdamage or aborting a test.

The automated test equipment 110 may be configured to adjust a test flowin response to the signal 142 received from the handler. The handler mayprovide information, e.g., temperature information, about devices undertest 152, 154, 156, 15 that can be used to adjust testing. For example,when the temperature of a device under test rises, the automated testequipment 110 may extend a delay period between two tests for to allowthe device to cool down and/or to prevent the device from reaching acritical temperature.

The automated test equipment 110 may be configured to interrupt a testin reaction to the signal 142 from the handler. In other words, thesignal 142 provided by the handler may be an interruption signal. Theautomated test equipment 110 may interrupt a test in response or inreaction to the signal 142, for example, based on an evaluation of atemperature measurement of the handler, by the handler, or based on anover temperature alert or alarm information provided by the handler 130.The handler 130 may also be configured to provide a test site specificinterruption signal to the automated test equipment via the testerinterface to allow an individual test interruption for a specific deviceunder test allowing tests of other devices under test to continue.Accordingly, the automated test equipment may be configured to generatea test site specific interrupt to interrupt a test in response toreceiving the test site specific signal from the handler.

The signal 142 provided by the handler 130 may be a deactivation signal,for example, for deactivating a power supply of one or more devicesunder test. In some cases, the handler 130 may not be able to preventoverheating of a device under test, e.g., in the case of a malfunction.Therefore, the handler may evaluate measurement data, and may send thedeactivation signal to the automated test equipment 110 to stop thepower supply of the device under test. In general, the handler may beconfigured to detect a malfunction, e.g., a device under testmalfunction or a temperature control malfunction, and may provideinformation to the automated test equipment 110 via signal 142, such asa deactivation signal. Accordingly, the automated test equipment may beconfigured to deactivate a power supply of one or more devices undertest in response to receiving a signal from the handler.

To prevent shutdown, the handler 130 may be configured to provide atemperature warning signal to the automated test equipment 110 via thetester interface 140. The automated test equipment can receive thetemperature warning signal and adapt the testing to prevent overheatingof a device under test 152, 154, 156, 158. Therefore, the handler 130may be configured to evaluate behavior or temperature measurements ofdevices under test during testing.

The automated test equipment 110 may be configured to receive a testsite specific signal from the handler 130. The handler may be configuredto provide the test site specific signal to the automated test equipmentvia the tester interface 140. Test functions may be performedindividually for a specific device under test or test site, such asindividual cooling strategies, power shutdowns, delay time adaptation,etc.

The handler 130 may be configured to handle the data of the device undertest using the signal 142 transmitted to the automated test equipment110 via the real-time tester interface 140. The automated test equipment110 may be configured handle the data of a device under test in responseto a reception of the signal 142 from the handler 130, for example. Thehandler may trigger a beginning or an end of a data record, such as whena malfunction or other event is detected, and the data may be recordedand stored for failure analyses. On the other hand, data recording canbe stopped when a malfunction or overheating occurs, such as when thepower supply to a device shuts down, which may render any measurementdata taken thereafter useless.

The handler 130 may be configured to provide a signal to the automatedtest equipment 110 via the tester interface 140 for logging by theautomated test equipment 110. The automated test equipment 110 may beconfigured to log the signal received from the handler 130. The signalmay include measurement data, e.g., temperature information, to bestored by the automated test equipment. Based on such data, a testevaluation may be performed.

According to some embodiments, the handler 130 is configured to providea signal to the automated test 110 equipment via the tester interface inreal-time for enabling a real-time reaction of the automated testingequipment 110 in response to the signal provided. For example, signal142 may be provided in real-time. As an example, the automated testequipment 110 may be configured to react in real-time in response to thesignal received by the handler 130. Providing handler information inreal-time and reacting in real-time allows for more efficient testingthat can be adapted and evaluated in real-time.

Some elements depicted in the example of FIG. 1 , such as the automatedtest equipment 110 and the handler 130, may include a test cell or atest system, according to some embodiments of the present invention.According to other embodiments, automated test equipment 110 and handler130 may be used individually. Signal 122, 142 may be transmitted over acommon wire, or over separate wires, according to embodiments.

FIG. 2 depicts a top view of exemplary automated test equipment 210 andan exemplary handler 230 using real-time interfaces 220, 240 accordingto embodiments of the present invention. FIG. 2 depicts an automatedtest equipment 210 including a real-time handler interface 220 and ahandler 230, including a real-time tester interface 240. Furthermore,FIG. 2 depicts devices under test 152, 154, 156, 158, as an example,arranged on the handler 230.

In the example of FIG. 2 , interfaces 220, 240 are real-time interfaces.Therefore, data transmission time between the interfaces, e.g. the timebetween the beginning of sending a message at the handler interface 220and the end of the arrival of the message at the tester interface 240,can be reduced to increase temperature control timing of a device undertest 152, 154, 156, 158, and information sent from the automated testequipment 210 to the handler 230 may be used for temperature control inreal-time.

The real-time handler interface 220 is configured to provide a triggersignal 122 to the handler 230 to trigger a temperature control function.The handler 230 is configured to receive the trigger signal 122 from theautomated test equipment 210 via the tester interface 240, and thehandler 230 is configured to trigger the temperature control function inresponse to the received signal 122.

The handler 230 may be configured to cool and/or heat a device undertest 152, 154, 156, 158, for example, to prevent overheating. Triggersignal 122 may include information about an upcoming temperature peak ofa device under test so that the handler can act to counter or prevent athermal hotspot (or even thermal runaway) of a device under test 152,154, 156, 158.

The real-time handler interface 220 is configured to provide asynchronization signal 222 to the handler 230 to synchronize functionsof the handler 230 beyond the triggering of the temperature controlfunction. For example, the handler 230 is configured to receive thesynchronization signal 222 from the automated test equipment 210 via thetester interface 240, and to synchronize functionality with theautomated test equipment 210 in response to the received synchronizationsignal 222.

Some applications, e.g., thermal diode calibration, may require fast andprecise synchronization timing between the handler 230 and the automatedtest equipment 210 to measure the temperature at the correct time. Thesynchronization signal 222 may be used to inform the handler 230precisely when to measure. This enables more precise testing as astimulus of a device under test can be aligned with a correspondingmeasurement of the handler 230.

According to some embodiments, the real-time handler interface 220 maybe configured to perform active synchronization with the handler basedon the synchronization signal 222 to the handler. The activesynchronization may include synchronization without using waitinsertions. The handler 230 may be configured to receive a signal fromthe automated test equipment 210 via the tester interface 240, e.g., thesynchronization signal 222, for active synchronization with theautomated test equipment 210. The handler may be configured to performthe active synchronization with the automated test equipment based onthe synchronization signal. This enables synchronizing handler 230 andautomated test equipment 210 to test faster and more accurately withouthaving to perform wait statements to achieve synchronization, which canreduce testing time and provide synchronization with very limited delay.

The real-time handler interface 220 may be configured to transmitcalibration timing information to the handler 230, and to determine thetiming for calibrating the handler 230. The handler 230 may beconfigured to receive the calibration timing information, e.g., via thesynchronization signal 222, from the automated test equipment 210 viathe tester interface 240, to determine a calibration timing.Furthermore, the handler 230 may be configured to determine thecalibration timing, based on the calibration timing information.Calibration may be performed to compensate for errors. For example, afirst measurement may be performed at a first state of a device undertest and the measurement data can be used to compensate for (e.g.,offset) subsequent measurements to increase measurement and/or testingaccuracy.

The real-time handler interface 220 may be configured to transmit asignal indicating that a device under test is powered, biased, orinitialized in a predetermined manner, for example, using thesynchronization signal 222. The handler 230 may be configured to receivethe signal from the automated test equipment 210 via the testerinterface 240 indicating that the device under test is conditioned,powered, biased, or initialized in the predetermined manner. Asexplained above, the information of a device under test being powered,biased, or initialized in a predetermined manner may be used tocalibrate subsequent measurements.

According to some embodiments, the real-time handler interface 220 maybe configured to transmit signals when different devices are tested orwhen specific test conditions are reached. The handler may be configuredto receive the signals from the automated test equipment 210 via thetester interface 240 to synchronize automated test equipment 210 andhandler 230, for example, using synchronization signal 222 or a separatesignal.

The automated test equipment 210 may be configured to provide thesynchronization signal 222 to trigger one or more temperature readingsby the handler 230. The handler 230 may be configured to receive asignal, for example the synchronization signal 222, from the automatedtest equipment 210 via the tester interface 240, and to calibrate orperform one or more temperature measurements based on thesynchronization signal. The automated test equipment may execute atesting routine, and may provide stimuli to the devices under test. Fortesting, temperatures of the devices may have to be measured when thedevices are in certain predetermined states. Based on the testingroutine and current stimulus, the automated test equipment may startsynchronization by instructing the handler 230 via the synchronizationsignal 222 to perform a measurement. Since the interfaces are real-timeinterface, the instruction can be transmitted quickly enough to performsynchronous measurements such that a measurement may be performed when arespective device is in its predetermined state as prescribed by thetesting routine, e.g., before the state of the device changes.

The real-time handler interface may be configured to enable thermaldiode calibration based on the synchronization signal to the handler230. The thermal diode calibration may include a delta temperaturemeasurement and the real-time handler interface 220 may be configured totransmit real-time measurement timing information to the handler 230 forthermal diode calibration.

The handler 230 may be configured to perform the thermal diodecalibration based on the synchronization signal 222 received from theautomated test 210 equipment via the tester interface 240. The thermaldiode calibration may include a delta temperature measurement and thehandler 230 may be configured to perform the delta temperaturemeasurement. Moreover, the handler may be configured to receivereal-time measurement timing information from the automated testequipment via the real-time tester interface for the thermal diodecalibration.

The synchronization signal 222 may include test site specific timeinformation for measurements of the handler 230. The synchronizationsignal includes test site specific test state information or devicestate information, for example. The automated test equipment 210 mayinform the handler 230 about an upcoming event, which may requirecertain measurements to be performed by the handler 210.

According to some embodiment, some elements shown in the example of FIG.2 may include a test cell or a test system, such as the automated testequipment 210 and the handler 230. Automated test equipment 210 andhandler 230 may be used individually. Signal 122, 222 may be transmittedover a common wire, or over separate wires, according to embodiments.

FIG. 3 depicts a top view of exemplary automated test equipment 310 andexemplary handler using a test site specific signal 322 according toembodiments of the present invention. FIG. 3 depicts an automated testequipment 310 including a real-time handler interface 320 and a handler330, including a real-time tester interface 340. FIG. 3 also depictsdevices under test 152, 154, 156, 158 arranged on the handler 330 as anexample.

The interfaces 320, 340 are real-time interfaces. Therefore, datatransmission times between the interfaces may be reduced to increase atemperature control timing of a device under test 152, 154, 156, 158,and information sent from the automated test equipment 310 to thehandler 330 may be used for temperature control in real-time.

The real-time handler interface 320 is configured to provide a test sitespecific signal 322 to the handler 330 for a temperature controlfunction, and the handler 330 is configured to receive the signal 322from the automated test equipment 310 via the tester interface 340. Thehandler 330 can control temperatures in response to the received testsite specific signal 322.

Devices under test 152, 154, 156, 158 may show different behavior, e.g.,different temperature trends and responses while testing. Therefore, theautomated test equipment 310 may provide test site specific informationfor adapting the temperature regulation of the devices under test. Thehandler may adapt the cooling order and magnitude of devices or testsites according to the information. Adapting testing to individual testsites can substantially increase testing efficiency.

As an example, signal 322 may include information regarding an upcomingtemperature peak of a specific device under test so that the handler canact to counter or prevent a thermal hotspot (or even a thermal runaway)of the device.

Test site specific signal 322 may include one or more of the following:a test site specific alarm, test site specific trigger identificationinformation, test site specific temperature adjustment information, testsite specific setup information, test site specific heat dissipationinformation, and/or test site specific timing information. Anyinformation that can be used to improve testing efficiency and accuracymay be transmitted using test site specific signal 322. An alarm may besent to the handler when the automated test equipment 310 determines atemperature hotspot, a device malfunction, or thermal runaway. Based ontest site specific setup information, the handler 330 may schedulecooling operations to optimally cool each device under test 152, 154,156, 158. Similarly, heat dissipation and timing information may beincluded in test site specific signal 322, such as the estimated orexpected heat that a device may dissipate according to a scheduled testor test stimulus, when the heat will be dissipated, or when the handlershould cool a certain device, which can improve testing efficiency andthermal management.

The test site specific signal may include test site identificationinformation and regulation information that can be associated with atest site. Temperature management strategies may be implementedindividually for each test site or device under test 152, 154, 156, 158to improve testing efficiency.

According to some embodiments, the test site identification informationincludes a test site ID, and the test site ID can be modulated on to thetest site specific signal. The test site ID can identify a specific testsite or device under test. A modulation of the test site ID may allowembodiments to use a single transmission line, e.g., a single triggerline, which can reduce wiring. Based on the ID, the handler 330 candetermine which test site acts in response to the trigger signal orsignal 322.

The regulation information may include timing information and/or controlamplitude information. Based on the regulation information, the handler330 can perform cooling/heating in order to keep the devices under testwithin a desirable temperature interval.

According to some embodiments, the automated test equipment 310 may beconfigured to provide a single trigger signal for a plurality of testsites with site-specific delay information describing delays between atrigger event and the beginning of thermal preconditioning operationsperformed for different test sites. The handler 330 may be configured toreceive the single trigger signal from the automated test equipment 310via the tester interface 320. In this way, the signal may be producedmore efficiently for faster signal transmission. The automated testequipment 310 may estimate or predict the occurrence an upcomingtemperature trend for a plurality of devices under test 152, 154, 156,158 and may determine, based thereon, adequate delays, e.g., coolingdelays, so that no device under test experiences thermal runaway.Accordingly, embodiments can delay the beginning of a testing operationor trigger event (e.g., an increase in power supply or a thermalpreconditioning operation). Moreover, devices may be given enough timeto cool down to a desirable temperature in between tests.

The automated test equipment 310 may be configured to execute test flowsof different test sites so that corresponding states are reached atdifferent times in different test flows, and the automated testequipment 310 can provide the site-specific signal in response toreaching predetermined states of the respective test flows. The handler330 can access the current state of each device under test 152, 154,156, 158, and can schedule adequate cooling operations accordingly.Moreover, the handler may be configured to start a cooling process for adevice under test before temperature rises, for example, based on atrigger signal including information pertaining to expected upcomingchanges in temperature. For example, the information can be based on acurrent or upcoming event, or a predetermined test state in a testingsequence. In addition, devices under test that receive a relatively highamount of power may be selected to perform more frequent temperaturemeasurements to monitor temperatures and prevent overheating.

Some elements depicted in the example of FIG. 3 may include a test cellor a test system, such as the automated test equipment 310 and/or thehandler 330. Automated test equipment 310 and handler 330 may be usedseparately and individually, according to embodiments.

FIG. 4 depicts a top view of exemplary automated test equipment 410 andan exemplary handler 430 using real-time interfaces 420, 440 and a testsite specific signal 422 according to embodiments of the presentinvention. FIG. 4 depicts an automated test equipment 410 including areal-time handler interface 420 and a handler 430 that includes areal-time tester interface 440. FIG. 4 depicts exemplary devices undertest 152, 154, 156, 158 arranged on the handler 430.

The interfaces 420, 440 are real-time interfaces. Data transmissiontimes between the interfaces may be reduced to increase a temperaturecontrol timing of a device under test 152, 154, 156, 158. Informationsent from the handler 430 to the automated test equipment 410 may beused for temperature control in real-time.

The real-time tester interface 440 is configured to provide the testsite specific signal 442 to the automated test equipment 410, and theautomated test equipment 410 is configured to receive the signal 442from handler 430 via the handler interface 420.

Devices under test 152, 154, 156, 158 may exhibit differentcharacteristics, e.g., different temperature trends, while testing.Accordingly, the handler 430 may provide test site specific informationfor adapting the temperature regulation or testing schedule of thedevices under test. For example, the handler may provide individualtemperatures of the devices under test 152, 154, 156, 158 for theautomated test equipment 410 under certain conditions. The automatedtest equipment 410 may therefor adapt delays between different tests fordevices or test sites according to the information to increase testingefficiency.

According to some embodiments, the handler 430 may be configured todetect a temperature malfunction. This may occur when a temperaturegradient exceeds a specific predetermined threshold or predefinedgradient. The test site specific signal may be a test site specificalarm, and the handler 430 may be configured to enable a test sitespecific alarm handling and/or a test site specific shutdown. Theautomated test equipment 410 may, optionally, be configured to handlethe test site specific alarm and/or to perform a test site specificshutdown based on the test site specific alarm. As an example, thehandler can detect a large temperature difference between measurementsof a device under test 152. The difference may exceed a threshold, andthe handler may issue an alert for device 152 or the associated testequipment. For example, a test site specific alarm may be transmittedvia signal 442 to the automated test equipment 410. The automated testequipment 410 may then shut down the specific test site (e.g., the testsite associated with device 152) to avert damage to the device and toenable further testing of the remaining devices under test 154, 156,158.

The handler 430 may be configured to adapt or influence the datahandling, e.g., the binning and datalogging, of the device under testusing the signal 442 transmitted to the automated test equipment 410 viathe real-time tester interface 440. The automated test equipment 410 maybe configured to influence the data handling of the device under test inresponse to a reception of a signal, e.g., a test site specific signal,from the handler 430. As an example, the handler 430 can detect amalfunction of a device under test as explained above and may thereforeinstruct the automated test equipment to prevent logging corrupted orinaccurate data.

The test site specific signal 442 may include a combination of test siteidentification information and regulation information, and the test siteidentification information may be used to associate the regulationinformation with a specific test site. As an example, a signal 442 mayinclude a syntax element identifying a particular test site or deviceunder test that is associated with thermal management information, suchas cooling amplitude or timing information (e.g., how long to cool andwhen to cool). In this way, testing may be performed with suitablethermal management for each device under test.

The test site identification information may include a test site ID, andthe test site ID can be modulated onto the test site specific signal442. Modulation of the test site ID may allow for a single trigger lineand may reduce wiring complexity, especially for a signaling a pluralityof test sites.

The regulation information can include timing information, e.g., fordetermining when to cool, heat, delay, or for controlling amplitudeinformation. This can allow for improved thermal management of thedevices under test.

Some elements shown in FIG. 4 may include a test cell or test system,such as the automated test equipment 410 and the handler 430, accordingto some embodiments. Automated test equipment 410 and handler 430 may beused individually as well.

FIG. 5 depicts automated test equipment 510 including a real-timehandler interface 520 and a handler 530 including a real-time testerinterface 540, according to embodiments of the present invention. In theexample of FIG. 5 , exemplary devices under test 152 154, 156, 158 arearranged on the handler 530.

The interfaces 520, 540 are real-time interfaces. Data transmission timebetween the interfaces can be reduced to increase a temperature controltiming of a device under test 152, 154, 156, 158. Accordingly,information sent from the automated test equipment 510 to the handler530 may be used for temperature control in real-time.

The real-time handler interface 520 is configured to provide a triggersignal 122 to the handler 530 to trigger a temperature control function.The handler 530 is configured to receive the trigger signal 122 from theautomated test equipment 510 via the tester interface 540, and thehandler 530 is configured to trigger the temperature control function inresponse to the received signal 122.

The handler 530 may be configured to cool and/or heat a device undertest 152, 154, 156, 158 to prevent overheating. Trigger signal 122 mayinclude information regarding an upcoming temperature peak of a deviceunder test, and the handler can counteract or prevent a thermal hotspot(or even a thermal runaway) of a device under test 152, 154, 156, 158.

Furthermore, the real-time handler interface 520 may be configured toprovide an additional signal 522, in addition to the trigger signal 122.The handler 530 may be configured to receive, via the real-time testerinterface 540, the trigger signal 122 and, in addition to the triggersignal, the additional signal 522. The additional signal may includecontrol information used to determine or modify a temperature controlprofile or temperature regulation by the handler, information regardingone or more measured values determined by the automated test equipmentor extracted from a device under test data stream by the automated testequipment, test state parameters, and/or alarm information.

Based on the testing to be performed, the automated test equipment 510may determine, predict, or evaluate the additional signal 522 tocoordinate interactions of the handler 530 with the devices under test152, 154, 156, 158. The automated test equipment 510 may predict risingtemperatures of a device under test, for example, due to a scheduledincrease in that amount of power provided, and may determine controlinformation for use by the handler to prevent the temperature fromreaching an undesirable level. This may include adjusting the coolingamplitude and/or cooling duration of the device under test. Furthermore,the automated test equipment 510 may determine information regarding oneor more measured variables and/or one or more test state parameters. Theautomated test equipment 510 may determine or evaluate a current orpredicted behavior of a device under test and provide and information tothe handler 530 for manipulating the device under test. For example, fordata evaluation, automated test equipment 510 determines a criticalstate, e.g., an overtemperature, of a device under test, and alarminformation may be provided to the handler 530 to allow the handler toadapt the management of the device, e.g., thermal management.

According to some embodiments, handler 530 may be configured todetermine a temperature control profile or temperature regulationprofile, and the handler 530 may be configured to determine a coolingamplitude and/or a duration and/or a cooling strength for thedetermination of the temperature control profile or temperatureregulation profile. The handler may evaluate the information provided bythe automated test equipment 510, e.g., in the form of trigger signal122, or of additional signal 522 to determine the temperature managementcharacteristics. Alternatively, such information may be evaluated by theautomated test equipment and transmitted directly, e.g., without thehandler having to determine the information.

According to some embodiments, the automated test equipment may beconfigured to extract a measured value or parameter from a digital datastream of the device under test, and the real-time handler interface isconfigured to transmit the measured value or parameter to the handlervia the real-time handler interface. The automated test equipment may beconfigured to transmit a value or parameter measured by an instrument ofthe automated test equipment to the handler via the handler interface.As described above, the handler 530 may evaluate, based on said measuredvalue, a state of a device under test, or a cooling amplitude and/orcooling strength, which can improve thermal management during testing.

According to some embodiments, the real-time handler interface 520 maybe configured to provide the additional signal 522 and/or trigger signal122 with a latency below 1 ms, below 100 microseconds, below 10microseconds, or below 1 microsecond, in different configurations. Forexample, the interfaces may run at a low latency for rapidly adaptingthe thermal management of the handler. The low latency data may berecent enough upon arrival to quickly counteract potential undesirableevents of a device under test, such as overheating.

According to some embodiments, the real-time handler interface 520 maybe configured to provide bandwidth so that the latency of the additionalsignal and/or of the trigger signal provided by the real-time handlerinterface is lower than a control loop timing of a temperature controlfunction. With data or signal transmission being faster than the controlloop timing, information transmitted may be used to improve or adapt thetemperature regulation.

According to some embodiments, the temperature control functions may usea control loop including the handler interface 520 and/or the testerinterface 540. The temperature control functions may be configured toconsider real-time information that is transmitted via the handlerinterface 520 and/or that may be received via the tester interface 540.For example, to provide robust and responsive temperature control, thecontrol loop may be provided with a plurality of information. Therefore,handler interface 520 and/or tester interface 540 may be part of thecontrol loop providing measurement data and/or evaluated parameters.Consequently, the current state of a device under test may becalculated, and a temperature of a device under test may be regulatedbased on a space state model. The model may be used for any kind ofcontrol. With the large amount of information, predictive controlconcepts may be implemented, e.g., based on estimated states similar toor associated with a current or estimated temperature of a device undertest. This may allow for robust and precise temperature control.

According to some embodiments, the control loop may include theautomated test equipment 510, and the automated test equipment 510 maybe configured to be part of an integrated regulation in combination withthe handler. The control loop may include the handler, and the handlermay be configured to be a part of an integrated regulator in combinationwith the automated test equipment. As explained above, a temperaturecontrol concept or function may include all elements, e.g. the automatedtest equipment and/or the handler, to aggregate all information channelsavailable, such as the measurement data of the handler, or the upcomingtests of a testing cycle. Therefore, testing efficiency is improved andadequate thermal management conditions are maintained.

According to some embodiments, the real-time handler interface 520and/or the real-time tester interface 540 may be configured to providesaid trigger 122 and/or additional signal 522 for real-time temperaturecontrol. For example, when interfaces 520, 540 are bidirectional, bothmay be configured to provide the signals 122, 522. The flow ofinformation may be chosen according to constraints of the specificapplication.

According to some embodiments, the handler 530 may include temperaturecontrol functionality. The handler may be configured to cool and/or heatdevices under test 152, 154, 156, 158. Therefore, the handler may be ormay include the control element of the control loop. In addition, usingthe information being transmitted via trigger signal 122 and triggersignal 522 from automated test equipment 510 to the handler 530, thehandler may determine an input variable for the temperature controller.

According to some embodiments, the real-time handler interface is partof a temperature regulation loop. According to other embodiments, thereal-time tester interface is part of a temperature regulation loop.

According to some embodiments, the automated test equipment 510 and/orthe handler 530 may be configured to implement integrated regulationfunctionality distributed between the automated test equipment and ahandler. The automated test equipment and/or the handler can calculatean input variable for use by a regulator or for scheduling temperaturecontrol inputs. Calculation of regulation data may be distributed in atime efficient way to minimize data transmission between the automatedtest equipment and the handler, for example, so that the majority ofdata transmitted includes final results required by the elementreceiving the data.

According to some embodiments, the automated test equipment 510 may beconfigured to affect a regulation using a pattern provided by a patterngenerator of the automated test equipment.

The elements shown in FIG. 5 may be a test cell or test system,including the automated test equipment 510 and the handler 530 accordingto embodiments of the invention. However automated test equipment 510and handler 530 may be used individually according to the invention. Thesignal 122, 522 may be made via common wire, or via separate wires.

FIG. 6 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process 600 for providing atrigger signal to a bidirectional dedicated real-time handler interfaceaccording to embodiments of the present invention. Process 600 includesstep 610 providing a trigger signal to a handler via a bidirectionaldedicated real-time handler interface to trigger a temperature controlfunction, step 620 receiving a signal from the handler via thebidirectional dedicated real-time handler interface, and step 630accessing, analyzing, or evaluating the signal received from thehandler.

FIG. 7 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process 700 for receiving atrigger signal from an automated test equipment via a bidirectionaldedicated real-time tester interface according to embodiments of thepresent invention. Process 700 includes step 710 receiving a triggersignal from an automated test equipment via a bidirectional dedicatedreal-time tester interface, step 720 triggering a temperature controlfunction in response to the received signal, and step 730 providing asignal to the automated test equipment via the tester interface.

FIG. 8 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process 800 for receiving atrigger signal from an automated test equipment via a bidirectionaldedicated real-time tester interface according to embodiments of thepresent invention. Process 800 includes step 810 providing a triggersignal to a handler to trigger a temperature control function via areal-time handler interface, step 820 providing a synchronization signalto the handler via the real-time handler interface, and step 830synchronizing another function of the handler (other than triggering thetemperature control function).

FIG. 9 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process 900 for receiving atrigger signal from an automated test equipment via a real-time testerinterface to trigger a temperature control function according toembodiments of the present invention. Process 900 includes step 910receiving a trigger signal from an automated test equipment via areal-time tester interface, step 920 triggering a temperature controlfunction in response to the received trigger signal, step 930 receivinga synchronization signal from the automated test equipment via thetester interface, and step 940 synchronizing another function with theautomated test equipment (other than triggering a temperature controlfunction in response to the received synchronization signal).

FIG. 10 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process 1000 for providing atest site specific signal to a handler via a real-time handler interfaceaccording to embodiments of the present invention. Process 1000 includesstep 1010 providing a test site specific signal to a handler via areal-time handler interface to control a temperature control function.

FIG. 11 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process 1100 for receiving atest site specific signal from an automated test equipment to control atemperature control function according to embodiments of the presentinvention. Process 1100 includes step 1110 receiving a test sitespecific signal from an automated test equipment via a tester interfaceand step 1120 controlling a temperature control function in response tothe received test site specific signal.

FIG. 12 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process 1200 for providing atest site specific signal to an automated test equipment according toembodiments of the present invention. Process 1200 includes step 1210providing a test site specific signal to an automated test equipment viaa real-time tester interface.

FIG. 13 is a flow chart depicting an exemplary sequence of computerimplemented steps of a computer-controlled process 1300 for receiving atest site specific signal from a handler via a real-time handlerinterface according to embodiments of the present invention. Process1300 includes step 1310 receiving a test site specific signal from ahandler via a real-time handler interface.

FIG. 14 is a flow chart depicting an exemplary sequence of computerimplemented steps of a process 1400 for providing a trigger signal via areal-time handler interface to a handler to trigger a temperaturecontrol function according to embodiments of the present invention.Process 1400 includes step 1410 providing a trigger signal via areal-time handler interface to a handler, to trigger a temperaturecontrol function, and step 1420 providing an additional signal, inaddition to the trigger signal via the real-time handler interface theadditional signal including a control information for a determination ormodification of a temperature control profile or temperature regulationby the handler, and/or an information about one or more measured valuesdetermined by the automated test equipment or extracted from a deviceunder test data stream by the automated test equipment, and/or one ormore test state parameters; and/or an alarm information.

FIG. 15 is a flow chart depicting an exemplary sequence of computerimplemented steps that perform a process 1500 of receiving a triggersignal and an additional signal via a real-time tester interfaceaccording to embodiments of the present invention. Process 1500 includesstep 1510 receiving, via a real-time tester interface, a trigger signal,and, in addition to the trigger signal, an additional signal whichincludes a control information for a determination or modification of atemperature control profile or a temperature regulation by the handlerand/or an information about one or more measured values determined bythe automated test equipment or extracted from a device under test datastream by the automated test equipment, and/or an alarm informationand/or one or more test state parameters, and step 1520 using theadditional signal to control the temperature of one or more devicesunder test sites.

It should also be noted that the present disclosure describes,explicitly or implicitly, features usable in an automated test system ortest cell. Thus, any of the features described herein can be used in thecontext of an automated test equipment for testing one or more devicesunder test or in a handler or in an automated test system or in a testcell for testing one or more devices under test (e.g., simultaneously orin a temporally overlapping manner at different sites).

Depending on certain implementation requirements, embodiments of theinvention can be implemented in hardware or in software. Theimplementation can be performed using a digital storage medium, forexample a floppy disk, a DVD, a Blu-Ray, a CD, a ROM, a PROM, an EPROM,an EEPROM or a FLASH memory, having electronically readable controlsignals stored thereon, which cooperate (or are capable of cooperating)with a programmable computer system such that the respective method isperformed. Therefore, the digital storage medium may be computerreadable.

Some embodiments according to the present invention include a datacarrier having electronically readable control signals, which arecapable of cooperating with a programmable computer system, such thatone of the methods described herein is performed.

Active temperature control (ATC) can be implemented as hardware and/orsoftware. For example, hardware can be used to measure the temperatureand software can be used to control the temperature. The ATC is (orincludes) a control loop going from handler to automated test equipmentor tester to device and back, which allows the handler to measure thedevice DIE temperature directly in the device.

In generally, the handler may measure the temperature on outside ofdevice. The ATC measures the templates (or the temperature) by theThermal diode in the DUT (e.g., device under test) and providesfeedforward control or feedback control.

FIG. 16 is a diagram depicting an exemplary automated test equipment1610 and a handler 130 with a test head 1614 according to embodiments ofthe invention. FIG. 16 depicts an automated test equipment 1610,optionally including a main frame 1612 and a test head 1614 and ahandler 1630. Automated test equipment 1610 and handler 1630 areoptionally connected with a first connection 1660, for example anethernet connection and a second connection 1670, for example a GPIBconnection. FIG. 16 depicts a device under test 1650, optionallyincluding a thermal diode, between automated test equipment 1610 or testhead 1614 respectively and handler 1630. In addition, handler 1630 andautomated test equipment 1610 or test head 1614 respectively are coupledwith a trigger signal line 1680, e.g., a pre-trigger signal line.Respective interfaces, e.g., tester interface and handler interface arenot explicitly shown. Trigger signal line 1680 may be configured toallow for a unidirectional or a bidirectional data exchange betweenautomated test equipment 1610 and handler 1630. Trigger signal line 1680may be configured to provide and/or receive the trigger signal and/orthe signal from the handler to the automated test equipment and/or thesynchronization signal and or any of the test site specific signalsand/or the additional signal, for example, in real-time.

Complex digital devices (which may serve as devices under test, DUT)such as CPUs (e.g., microprocessors), GPUs (e.g., graphics processingunits) and MCUs (e.g., microcontrollers) may consume a large amount ofpower. Power consumption and device temperature profile may varythroughout test and can be even test site dependent. Precise temperaturecontrol may be important or even essential to test these devices with a“flat” and/or predictable temperature profile. To achieve this a testcell (e.g., tester and handler) may analyze and combine different typesof source data in real-time. In contrast to traditional testing wherethe handler controls the temperature by only measuring the test chambertemperature, the ATC can provide the handler with additional deviceand/or tester information to precisely control and/or forecast potentialtemperature hot spots.

FIG. 17 depicts an exemplary temperature control function according toembodiments of the invention. FIG. 17 depicts a device 1750, e.g.,device under test, an automated test equipment 1710 and a handler 1730.The automated test equipment 1710 may, for example receive, determine,and/or evaluate information from or based on the device under test 1750(e.g., information 1760), which may include test parameters, controlinformation, and/or test state parameters. The information may befurther processes and provided to the handler 1730. The informationprovided by the automated test equipment 1710 to the handler 1730 may beany information suitable for improving testing and/or thermal regulationefficiency, e.g., device state or device status, or a predictedtemperature course of the device 1750 based on a testing cycle. Thehandler may then control 1770 the temperature of the device 1750 basedon the information provided by the automated test equipment andtemperature measurements of the handler 1730 for said device 1750.Temperature calibration for the device’s thermal diode may be used tocancel-out and/or reduce silicon fabrication dependencies. Site-specificalarm handling and shutdown may, in some cases, be used to alert theautomated test equipment or tester, if the handler detect a temperaturerun-away. The trigger capability, e.g., pre-trigger capability can beextended to allow a precise, fast synchronization and/or data exchangebetween tester (e.g., an automated test equipment) and handler and/orvice versa.

Trigger extension, e.g., pre-trigger extension, can enable fast, lowlatency, real-time and/or bidirectional communication, for example,between tester and handler using pre-trigger technology. Trigger line orwire, e.g., pre-trigger line or wire can be used to modulate and/ortransport data between automated test equipment. Data or information,such as “per site ALARM”, “per site power shutdown”, “site specificpre-trigger IDs” (e.g., for test flow branching), and/or “site dependentcooling information” can be sent in real-time between the equipment.This fast interface can reduce the amount hardware that is needed forper site pre-trigger and/or alarm handling interface, down to anexisting single line, or wire, trigger, e.g., pre-trigger, interface.

When the handler cannot cool the device anymore or does not receive thetemperature from the device thermal diode, in some cases it may beadvantageous or even required to disconnect the device under test fromthe power supply. Otherwise, it may destroy the test setup. Some devicescan go to 500-800 W.

In some cases, applications are required to send test site specificinformation in real-time to the handler. For instance, some devices havea different test setup (e.g., VDD voltage) which may lead to more heatdissipation. Therefore, the handler can be informed upon reaching atrigger point to ensure that no under-cooling/over-heating happens.

FIG. 18 depicts two exemplary test sites, a first test site 1810, Site 1and a second test site 1820, Site N according to embodiments of thepresent invention. As a part of a testing routine, a test suite burst1830 can be applied to the test sites. The test sites 1810 and 1820 mayreceive a trigger signal 1840, for example a common trigger orpre-trigger. For each test site 1810, 1820, an example of atemperature-over-time diagram for a DIE temperature is shown. At astarting time, the first site 1810 may have a lower DIE temperature thanthe second site 1820. Embodiments may be configured to take sitedependent temperatures into account. As explained above, the handler, orthe temperature control, e.g., in the handler, may be informed at thetrigger point as shown by trigger signal 1840, close to the 0 s time, ofa site characteristic, e.g., the second site 1820 being hotter.Therefore, the delay of the second, hotter site 1820 may be reduced toallow for a longer “cool down” time. As shown in FIG. 18 , the first,cooler site 1810 may receive a longer delay time, e.g., 120 ms than thehotter second site 1820, receiving a shorter delay time e.g., 100 ms. Insome cases, a handler may delay a cooling for a shorter period of timein case of a hotter test site to allow for a longer cool down timebefore the next stimulus. In this way, cooling of devices under test maybe scheduled, to keep all devices under test in a desirable temperaturerange. In addition to the trigger signal, there may be additionalsite-specific information (e.g., modulated data).

During testing, some test sites may be executed in different branches.In some cases, this may require hardware trigger lines, e.g.,pre-trigger-lines per test site. Alternatively, a single trigger line,e.g., pre-trigger line can be used, for example by identifying thetrigger/pre-trigger with modulated test site ID (identification)information. Via the ID, the handler may be informed, which test site,or “short site,” should act on the trigger/pre-trigger signal. Othertest sites may ignore the trigger/pre-trigger. In the example of FIG. 19, test site 1 ignores pre-trigger #2.

FIG. 19 depicts an exemplary test flow (e.g., using test suites)according to embodiments of the present invention. FIG. 19 depicts afirst trigger signal 1910 (pre-trigger #1). The first trigger signal1910 may influence, or may be taken into account by the first and secondtest site 1920, e.g., test sites 1 and 2. As an example, a secondtrigger signal 1930 (pre-trigger #2) may influence, or may be taken intoaccount only by the second test site 1940. A third trigger signal 1950(pre-trigger #3) may influence, or may be taken into account by thefirst and second test site 1920.

In some cases, to protect the test setup, the handler may be configuredto detect a so called “temperature run-away”. This may occur when thetemperature reading in the ATC loop is broken, for example, due to adefective thermal diode or cable. In this case, the handler may shutdown a specific test site immediately, and may influence the datahandling, or the binning and/or datalogging of the device, for example,while executing a test program. Instead of using a hardware interfacethat has an ALARM wire per test site, a fast, low latency interface canperform this task by modulating the site information onto the existingtrigger signal or pre-trigger signal. This information can be decoded onthe automated test equipment side or tester side and may shut down asite-specific power supply.

FIG. 20 depicts an exemplary alarm handling process according toembodiments of the present invention. FIG. 20 depicts a device 1750, anautomated test equipment 1710, e.g., tester, and a handler 1730. FIG. 20depicts different malfunctions that may occur alone or in combination,and that may be addressed by embodiments of the invention. For example,the device 1750 may suffer a malfunction 2010, e.g., a thermalmalfunction, or device 1750 may suffer from a defect. In this case, theautomated test equipment 1710, may detect the malfunction, or maydetermine that data has not been received from the device, and determinethat a malfunction has likely occurred, as shown by arrow 2020. Asanother example, a signal 2030 between automated test equipment 110 andhandler may be disturbed and suffer a malfunction 2040. As an example, awire may be broken. As another example, the device temperature can“run-away” 2050, or the handler may detect 2060 a temperature“run-away”. As explained above, in the case of malfunctions 2010 or2050, the automated test equipment and/or the handler may detect such amalfunction based on temperature measurements. The handler may cool sucha device, or the automated test equipment may shut down a correspondingtest site. For example, to coordinate adequate countermeasures, thehandler may be configured to trigger an alarm. The handler 1730 maytrigger a device shutdown in real-time as shown by arrow 2070.

The trigger, e.g., pre-trigger, can support precise equipmentsynchronization. As an example, thermal diode temperaturecharacteristics (e.g., diode reverse current) can be highly processdependent. This can be eliminated in test by a delta temperaturemeasurement, which may require fast and precise synchronization timingbetween the handler and the automated test equipment or tester tomeasure the temperature at the correct point, for example, at a certainpoint in time and/or at a certain location on the device under test.Measurement can be taken under different device or test conditions suchas unpowered and powered, for example, to compensate for leakagecurrent, device turn on leakage current, or heating effects that mayaffect temperature measurement during this calibration step.

An advanced trigger signal, such as a pre-trigger, can be used to informthe handler precisely when to measure, for example, to calibratebaselines (e.g., P1 shown in FIG. 21 ). The baseline may be used forfollowing temperature measurement as reference, for example, tocompensate for errors. Alternatively, active synchronization may help toachieve significant test time reduction. In some cases, this can reduceor eliminate the use of WAIT insertions and/or can reduce or eliminatemeasurements taken under incorrect test conditions to prevent incorrector inaccurate test results. By not having wait times, test time may besignificantly reduced.

FIG. 21 depicts an exemplary calibration function according toembodiments of the present invention. including optional device status2110, test execution 2120 and trigger signal 2130, which may be atrigger or pre-trigger. For example, the device may be inserted andoptionally, the handler may provide a handler information 2140 (HandlerStartOfTest), the device status 2110 that indicates that the device isin its place, and a predetermined test site/test may be started. In aPre-Test phase 2150 of the test execution, a pre-test temperature 2160may be triggered by the trigger signal 2130. For example, trigger P1 maybe measured, as a reference. According to some embodiments, the fast,real-time, interfaces inform the handler in real-time which avoids theneed for WAIT statements, and the device under test is made ready forthe calibration measurement via trigger P1. Following calibration, atesting may be performed, such as an active device test 2170 of the testexecution 2120. Rising temperature during testing are signaled usingadditional trigger signals or trigger pulses (P2, P3, Pn) provided viathe trigger signal 2130.

According to some embodiments, a first trigger signal or trigger pulseP1 may signal that the device under test is ready for a referencemeasurement. In other words, a first trigger signal or a first triggerpulse P1 after testing has started may indicate that the device undertest is ready for a reference temperature measurement, and may beinterpreted by the handler to trigger such a reference temperaturemeasurement (which may be based on an evaluation of a signal provided bya temperature measurement diode on the device under test). In otherwords, the first trigger signal or first trigger pulse after testing hasstarted may indicate that a device under test is inserted in a testposition and (optionally) biased appropriately to allow for thereference temperature measurement by the handler (e.g., using thetemperature measurement structure on the device under test).

Additional trigger signals or trigger pulses (e.g., after the firsttrigger signal or trigger pulse within a test or test sequence) may bepre-trigger information signaling an expected upcoming temperature rise.Accordingly, the further trigger signals or trigger pulses may beinterpreted by the handler as a pre-trigger signal, e.g., to activate acooling in advance of a temperature rise.

Optionally, a second trigger pulse (P2) may indicate that the device isactive (e.g., fully powered). However, the second trigger pulse(following the first trigger pulse) may already be a pre-trigger signal.

For example, the handler may take the reference temperature measurementin response to the first trigger pulse, and may then continuously (orrepeatedly) make further temperature measurements. For example, thehandler may use the reference temperature measurement for calibrationpurposes, e.g., to remove certain characteristics of a temperaturemeasurement structure on the device under test from the furthertemperature measurements.

Other test parameters, besides the thermal diode information, maycontribute to a better forecast and regulation behavior of device hotspots for early or predictive determination of cooling amplitude,duration, strength, for example, of each test site. A fast trigger,e.g., pre-trigger, and communication channel between handler andautomated test equipment can be used to transport the data, e.g.,parameter data or controlling parameters.

TABLE I Parameter Data Examples (non-limiting) Parameter DescriptionPMON Monitoring real-time DUT power consumption Tj Actual DUT junctiontemperature SPT Synchronous trigger, e.g. pre-trigger, signal thatalerts an upcoming power hot spot SITE Site specific control data DUTDUT specific control data TEST Test specific response data FLOW Test subflow specific control data

Exemplary Controlling Parameters that may be used:

-   h. Information of an upcoming temperature hot spot;-   i. duration of the hot spot;-   j. amplitude of the hot spot; and-   k. site and device specific temperature control data.

Any of the interfaces, e.g., tester interface and or handler interfacemay be bidirectional, and/or dedicated, real-time interfaces. Adirection of information transmission, e.g., only in one direction orboth directions, may be chosen according to a specific application. Inaddition, any of the signals and information provided may be a test sitespecific information, from automated test equipment to handler or viceversa. Signals may be provided or received in any configuration oftester and handler interface. In addition, signals may include aplurality of information, e.g., a trigger information, a synchronizationinformation and/or additional information. However, this information mayas well be provided or received as distinct signals, e.g., one signalfor a specific information. In addition, any of the signal or acombination thereof may be transmitted via a single channel.

Embodiments of the present invention are thus described. While thepresent invention has been described in particular embodiments, itshould be appreciated that the present invention should not be construedas limited by such embodiments, but rather construed according to thefollowing claims.

What is claimed is:
 1. Automated test equipment for testing a deviceunder test (DUT), the automated test equipment comprising: a testcomputer; and a real-time handler interface coupled to a handler,wherein the real-time handler interface is operable to: transmit atrigger signal from the test computer to the handler to trigger atemperature control function of the handler; and transmit asynchronization signal from the test computer to the handler tosynchronize another function of the handler, other than the temperaturecontrol function, in real-time.
 2. The automated test equipment asdescribed in claim 1, wherein the real-time handler interface is furtheroperable to perform an active synchronization with the handler based onthe synchronization signal, and wherein the active synchronization isfree of any wait insertions.
 3. The automated test equipment asdescribed in claim 1, wherein the real-time handler interface isoperable to transmit calibration timing information to the handler, andwherein the handler is operable to perform calibration of the handlerbased on the calibration timing information.
 4. The automated testequipment as described in claim 1, wherein the real-time handlerinterface is further operable to transmit another signal indicating thatthe DUT is powered or biased in a predetermined manner.
 5. The automatedtest equipment as described in claim 1, wherein the real-time handlerinterface is further operable to transmit another signal when apredetermined test condition is satisfied.
 6. The automated testequipment as described in claim 1, wherein the real-time handlerinterface is further operable to provide the synchronization signal tothe handler to trigger a temperature measurement by the handler.
 7. Theautomated test equipment as described in claim 1, wherein the handler isoperable to perform a thermal diode calibration according to thesynchronization signal, and wherein the thermal diode calibrationcomprises a delta temperature measurement, and wherein further thereal-time handler interface is further operable to transmit real-timemeasurement timing information to the handler for performing the thermaldiode calibration.
 8. The automated test equipment as described in claim1, wherein the synchronization signal comprises time information forperforming a measurement by the handler.
 9. The automated test equipmentas described in claim 1, wherein the synchronization signal comprises atleast one of: test state information; and device state information. 10.A handler for testing a device under test (DUT) using automated testequipment, the handler comprising: a circuit; and a real-time testerinterface coupled to the DUT, wherein the circuit is operable to:receive a trigger signal from the automated test equipment; trigger atemperature control function in response to the received trigger signal;receive a synchronization signal from the automated test equipment; andsynchronize another function with the automated test equipment, otherthan the temperature control function, in response to the receivedsynchronization signal.
 11. The handler as described in claim 10,wherein the circuit is further operable to: receive a signal forperforming an active synchronization with the automated test equipment;and perform active synchronization with the automated test equipmentbased on the synchronization signal, and wherein the activesynchronization is free of any wait insertions.
 12. The handler asdescribed in claim 10, wherein the circuit is further operable to:receive calibration timing information from the automated test equipmentto determine calibration timing; and perform calibration to test the DUTbased on the calibration timing information.
 13. The handler asdescribed in claim 10, wherein the circuit is further operable toreceive another signal from the automated test equipment, wherein theanother signal indicates that the DUT is powered or biased in apredetermined manner.
 14. The handler as described in claim 10, whereinthe circuit is further operable to receive a signal from the automatedtest equipment when a predetermined test condition is satisfied.
 15. Thehandler as described in claim 10, wherein the circuit is furtheroperable to: receive another signal from the automated test equipmentthat triggers a temperature reading; and perform the temperaturemeasurement based on the synchronization signal.
 16. The handler asdescribed in claim 10, wherein the circuit is further operable to:perform a thermal diode calibration based on the synchronization signalreceived from the automated test equipment, wherein the thermal diodecalibration comprises a delta temperature measurement; perform the deltatemperature measurement; and receive real-time measurement timinginformation from the automated test equipment for performing the thermaldiode calibration.
 17. The handler as described in claim 10, wherein thesynchronization signal comprises time information, and wherein thereal-time tester interface is further operable to cause the circuit toperform a measurement based on the time information.
 18. The handler asdescribed in claim 10, wherein the synchronization signal comprises atleast one of: test state information; and device state information. 19.A method of testing a device under test, the method comprising:transmitting a trigger signal to a handler via a real-time handlerinterface to trigger a temperature control function of the handler;transmitting a synchronization signal to the handler via the real-timehandler interface; and synchronizing another function of the handleraccording to the synchronization signal, other than the temperaturecontrol function.
 20. A method of testing a device under test, themethod comprising: receiving a trigger signal from an automated testequipment via a real-time tester interface; triggering a temperaturecontrol function in response to the received trigger signal; receiving asynchronization signal from the automated test equipment via thereal-time tester interface; and synchronizing another function with theautomated test equipment, other than the temperature control function,in response to the received synchronization signal.